FR3058368A1 - SEAT AND SEAT BACKREST FOR MOTOR VEHICLE SEAT - Google Patents

Abstract

The invention relates to a padding comprising a web (4) heating comprising an electric circuit (5) based on conductive ink, said circuit comprises at least one first (7) and at least one second (8a, 8b) bus s' extending longitudinally, said buses being interconnected by a plurality of microcircuits (12) printed shaped to form resistors capable of heating said padding, said padding having any of the following features: said buses are based on a first ink and said microcircuits are based on a second ink, said first ink having an intrinsic conductivity greater than that of said second ink; or said buses and microcircuits are based on the same ink, said ink being deposited in greater thickness for said buses than for said microcircuits, so that said buses oppose a minimized electrical resistance to the passage of current.

Description

058 368

60698 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number:

(to be used only for reproduction orders)

©) National registration number

COURBEVOIE © Int Cl ⁸ : B 60 N2 / 56 (2017.01)

PATENT INVENTION APPLICATION

A1

©) Date of filing: 04.11.16. (© Applicant (s): CERA TSC Société par actions simpli- (30) Priority: trusted - FR. @ Inventor (s): GEORGES LAURENT, SANCHEZ SANTIAGO and PUIG LLUIS. (43) Date of public availability of the request: 11.05.18 Bulletin 18/19. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ©) Holder (s): CERA TSC Société par actions simpli- related: trusted. ©) Extension request (s): (© Agent (s): STRATO-IP Limited liability company.

p4) MOTOR VEHICLE SEAT OR SEAT BACKREST.

FR 3 058 368 - A1

The invention relates to a padding comprising a heating sheet (4) comprising an electrical circuit (5) based on conductive ink, said circuit comprises at least a first (7) and at least a second (8a, 8b) bus s' extending longitudinally, said buses being interconnected by a plurality of printed microcircuits (12) shaped so as to form resistors capable of heating said padding, said padding having either of the following characteristics: said buses are based on a first ink and said microcircuits are based on a second ink, said first ink having an intrinsic conductivity greater than that of said second ink; or else said buses and microcircuits are based on the same ink, said ink being deposited in greater thickness for said buses than for said microcircuits, so that said buses offer minimized electrical resistance to the passage of current.

The invention relates to a padding for a seat or backrest of a motor vehicle seat and a seat comprising such padding.

It is known to produce padding for a seat or backrest of a motor vehicle seat, said padding comprising:

• a padding block based on elastically compressible material, • a covering cap of said block, • a heating sheet interposed between said block and said cover, said sheet comprising an electrical circuit based on conductive ink, said ink being based on a polymeric binder in which conductive particles are dispersed, said ink being printed on a support, said padding having the following characteristics:

• said circuit comprises at least a first and at least a second bus extending longitudinally • said first bus is provided with a first connection point intended to be connected to a first pole of an electric generator and said second bus is provided a second connection point intended to be connected to a second pole of said generator, said connection points being located along an edge of said padding, • said buses are connected together by a plurality of printed microcircuits shaped so as to form resistors capable of heating said padding by passing an electric current.

The realization of an electrical circuit based on printed conductive ink, in comparison with achievements involving metal cables, has the advantage of allowing great freedom in the geometric definition of said circuit.

In particular, it is easy to provide zones without a circuit in order to allow the passage of anchoring members - for example in the form of hooks - from the cap securely to the padding block - said hooks being anchored for example on a metal wire overmolded by said block on its reverse side.

However, by its constitution, such an ink is less conductive, with isosection, than a metal cable which has negligible resistance.

As a result, the resistance against current flowing in a bus increases markedly as one moves away from its connection point.

This results in a passage in the microcircuits of a decreasing current intensity as said microcircuits are distant from the connection points, which results in a corresponding reduction in heating.

Consequently, the padding is all the less heated as one moves away from the connection points.

The object of the invention is to overcome this drawback.

To this end, and according to a first aspect, the invention provides padding for the seat or backrest of a motor vehicle seat, said padding comprising:

• a padding block based on elastically compressible material, • a covering cap of said block, • a heating sheet interposed between said block and said cover, said sheet comprising an electrical circuit based on conductive ink, said ink being based on a polymeric binder in which conductive particles are dispersed, said ink being printed on a support, said padding having the following characteristics:

• said circuit comprises at least a first and at least a second bus extending longitudinally • said first bus is provided with a first connection point intended to be connected to a first pole of an electric generator and said second bus is provided a second connection point intended to be connected to a second pole of said generator, said connection points being located along an edge of said padding, • said buses are connected together by a plurality of printed microcircuits shaped so as to form resistors capable of heating said padding by the passage of an electric current, said padding additionally having any of the following characteristics:

• said buses are based on a first ink and said microcircuits are based on a second ink, said first ink having an intrinsic conductivity greater than that of said second ink, • or else said buses and microcircuits are based on the same ink, said ink being deposited in greater thickness for said buses than for said microcircuits, so that said buses oppose minimized electrical resistance to the passage of current.

In this description, the terms of positioning in space (longitudinal, transverse, lateral, horizontal, lower, etc.) are taken with reference to a seat cushion placed in the position of use in the vehicle and to a cushion backrest folded horizontally, along an axis of rotation extending at the lower edge of said backrest when it is in the use position.

With the proposed arrangement, the electrical resistance of the buses is minimized, which allows a substantially homogeneous supply of the various microcircuits, regardless of their distance from the connection points.

This results in substantially uniform heating of the padding on its receiving surface for a passenger.

According to a second aspect, the invention provides a seat comprising such padding.

Other features and advantages of the invention will appear in the following description, made with reference to the attached figures, in which:

• Figure 1 is a schematic sectional representation of a padding according to an embodiment, • Figure 2 is a schematic representation front view of a circuit according to an embodiment.

Referring to the figures, a padding 1 for a seat or a backrest of a motor vehicle seat is described, said padding comprising:

• a padding block 2 based on elastically compressible material, • a cover 3 for coating said block, • a heating sheet 4 interposed between said block and said cover, said sheet comprising an electrical circuit 5 based on conductive ink , said ink being based on a polymeric binder in which conductive particles - for example metallic particles - are dispersed, said ink being printed on a support 6, said padding having the following characteristics:

• said circuit comprises at least a first 7 and at least a second 8a, 8b bus extending longitudinally • said first bus is provided with a first connection point 9 intended to be connected to a first pole of an electric generator and said second bus is provided with a second connection point 10a, 10b intended to be connected to a second pole of said generator, said connection points being located along an edge 11 of said padding, • said buses are interconnected by a plurality of printed microcircuits 12 shaped - in twists according to the embodiment shown - so as to form resistors capable of heating said padding by the passage of an electric current, said padding additionally having any of the following characteristics:

• said buses are based on a first ink and said microcircuits are based on a second ink, said first ink having an intrinsic conductivity greater than that of said second ink, • or else said buses and microcircuits are based on the same ink, said ink being deposited in greater thickness for said buses than for said microcircuits, so that said buses oppose minimized electrical resistance to the passage of current.

Obtaining better conductivity for the first ink than for the second can be achieved in various ways, for example by taking conductive particles of better conductivity, by increasing their rate, etc.

According to the embodiment shown, the padding 1 comprises:

• a first single bus 7 located in the central part of said padding, so that said bus forms central bus 7, • two second buses 8a, 8b arranged laterally and symmetrically on either side of said central bus, so that said second buses form side buses 8a, 8b, each of said side buses being provided with a second connection point 10a, 10b,

In a variant not shown, it can be provided that the first bus 7 comprises a central slot so as to be in the form of two parallel sub-buses, said slot allowing the passage of anchoring members of the cover 3 integrally with the block 2.

In a variant not shown, one can provide a first 7 and a second 8a bus arranged laterally on either side of the padding 1, the microcircuits 12 extending transversely between said buses.

Such an embodiment makes it possible to preserve the central part of padding 1 from the presence of a bus 7 which could prevent the installation of means for fixing the cap 3 on the block 2.

According to the embodiment shown, the buses 7,8a, 8b are generally in front view in the form of strips of constant width, the width 18 of the central bus 7 being substantially double that of the side buses 8a, 8b.

Thus, at iso-thickness of ink for the first 7 and second 8a, 8b bus, a fluid flow of current is ensured from one terminal to the other of the generator, without "bottleneck".

According to the embodiment shown, the width 18 of the central bus 7 is between 1.8 and 2.2 times the width 19 of the side buses 8a, 8b.

According to the embodiment shown, the microcircuits 12 are placed on pads arranged symmetrically with respect to the central bus 7, so as to allow symmetrical heating of the padding 1.

According to the illustrated embodiment:

The central bus 7 is provided with at least a first and a second pair of transverse branches 13a, 13b, 14a, 14b extending along the length of said bus, two branches of a given pair pointing respectively to one and the other of the side buses 8a, 8b, • said side buses are each provided with reciprocal branches 15a, 15b transverse pointing towards said central bus, each of said reciprocal branches being connected to a respective branch 13a, 13b, 14a, 14b of said central bus by a plurality of microcircuits 12, said plurality forming a heating sub-circuit 16.

According to the embodiment shown, the branches 13a, 13b, 14a, 14b and reciprocal branches 15a, 15b have a width which decreases as we move towards their free end.

According to one embodiment, the width of the microcircuits 12 of a heating sub-circuit 16 increases as said sub-circuit is moved away from the connection points 9, 10a, 10b.

Such an arrangement makes it possible to compensate for a slight decrease in the intensity of the current in the microcircuits 12, as they are distant from the connection points 9, 10a, 10b, which results from the fact that the buses 7,8a, 8b do not are not perfectly conductive.

According to various embodiments, the support 6 receiving the printed electrical circuit 5 is formed as desired by:

• a flexible layer 17 interposed between the cover 3 and the block 2, according to the embodiment shown, • or the face of said block intended to receive an occupant of the seat, according to an embodiment not shown, • or the reverse face of said cover , according to an embodiment not shown.

According to the embodiment shown, the support 6 receiving the printed electrical circuit 5 being formed by a flexible layer 17 interposed between the cover 3 and the block 2, the circuit 5 is turned towards said block so that it is optimally protected.

Finally, there is described, not shown, a motor vehicle seat comprising such padding 1, said padding being mounted integrally with a frame of said seat, the connection points 9, 10a, 10b being located on the edge 11 of said padding, said edge being disposed in the junction zone between the seat and the backrest.

Such an arrangement makes it possible to guarantee great robustness of the connection points 9, 10a, 10b which are not mechanically stressed by a passenger bearing on the padding 1.

Claims (10)

1. Padding (1) for a seat or backrest of a motor vehicle seat, said padding comprising: • a block (2) of padding based on elastically compressible material, • a cover (3) for coating said block, • a heating sheet (4) interposed between said block and said cover, said sheet comprising an electrical circuit ( 5) based on conductive ink, said ink being based on a polymeric binder in which conductive particles are dispersed, said ink being printed on a support (6), said padding having the following characteristics: • said circuit comprises at least a first (7) and at least a second (8a, 8b) bus extending longitudinally, • said first bus is provided with a first connection point (9) intended to be connected to a first pole of an electric generator and said second bus is provided with a second connection point (10a, 10b) intended to be connected to a second pole of said generator, said connection points being situated along an edge (11) of said padding , • said buses are interconnected by a plurality of printed microcircuits (12) shaped so as to form resistors capable of heating said padding by passing an electric current, said padding being characterized in that it has a choice of l any of the following: • said buses are based on a first ink and said microcircuits are based on a second ink, said first ink having an intrinsic conductivity greater than that of said second ink, • or else said buses and microcircuits are based on the same ink, said ink being deposited in greater thickness for said buses than for said microcircuits, so that said buses oppose minimized electrical resistance to the passage of current. 2. Padding according to claim 1, characterized in that it comprises: • a first single bus (7) located in the central part of said padding, so that said bus forms central bus (7), • two second buses (8a, 8b) arranged laterally and symmetrically on either side of said central bus , so that said second buses form side buses (8a, 8b), each of said side buses being provided with a second connection point (10a, 10b), 3. Padding according to claim 2, characterized in that the buses (7,8a, 8b) are generally presented in front view in the form of strips of constant width, the width (18) of the central bus (7) being substantially the double that (19) of the side buses (8a, 8b). 4. Padding according to claim 3, characterized in that the width (18) of the central bus (7) is between 1.8 and 2.2 times the width (19) of the side buses (8a, 8b). 5. Padding according to any one of claims 2 to 4, characterized in that the microcircuits (12) are placed on pads arranged symmetrically with respect to the central bus (7). 6. Padding according to any one of claims 2 to 5, characterized in that: • the central bus (7) is provided with at least a first and a second pair of transverse branches (13a, 13b, 14a, 14b) extending along the length of said bus, two branches of a given pair pointing respectively towards one and the other of the lateral buses (8a, 8b), • said lateral buses are each provided with reciprocal branches (15a, 15b) transverse pointing towards said central bus, each of said reciprocal branches being connected to a respective branch (13a , 13b, 14a, 14b) of said central bus by a plurality of microcircuits (12), said plurality forming a heating sub-circuit (16). 7. Padding according to one of claim 6, characterized in that the branches (13a, 13b, 14a, 14b) and reciprocal branches (15a, 15b) have a width narrowing as one goes towards their end free. 8. Padding according to any one of claims 1 to 7, characterized in that the width of the microcircuits (12) of a heating sub-circuit (16) increases as said sub-circuit is moved away from the connection points ( 9.10a, 10b). 9. Padding according to any one of claims 1 to 8, characterized in that the support (6) receiving the printed electrical circuit (5) is formed as desired by: A flexible layer (17) interposed between the cap (3) and the block (2), 15 · or the face of said block intended to receive an occupant of the seat, • or the reverse face of said cover. 10. Motor vehicle seat comprising a padding according to any one of claims 1 to 9, said padding being mounted integrally with a frame of said seat, the connection points (9,10a, 10b) being located on the edge (11) of said padding, said edge being disposed in the junction zone between the seat and the backrest.